Comparison

NumberBook vs PDF Reader Light & Simple

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

NumberBook

Instantly identify unknown callers and protect yourself from scams with a vast global database. Perform reverse phone lookups to discover caller identity, location, and user-reported categories like spam or trustworthy. Block unwanted numbers with a personalized blacklist.

Highlights
  • Unknown call identification
  • Reverse phone lookup
  • Spam and scam protection
  • Company and business identification
  • Customizable blacklist
  • User-reported number categories
Features
Read full description

Finding unknown numbers was never easier! Identify up to 99% of unknown calls with NumberBook: Who Is Calling. Our global database of 52 million analyzed numbers and companies instantly protects you from known phone scams. Our phone book is here to help you understand who is on the other end of the line. But wait - there is more! Who Is Calling isn't an ordinary number book. Through reverse phone lookup, you can see the number's identity, country, and even location. You can finally live spam-call-free and never miss a legitimate phone call again! WHY TO USE NUMBER BOOK: WHO IS CALLING? It's fast - type in an unknown number; the number book will identify it and give you context on who's calling. It's easy - Number Book: Who Is Calling makes phone number lookup pleasant and straightforward. It's secure - Number Book: Who Is Calling does not gather or monitor your personal data. ALL NUMBER BOOK: WHO IS CALLING FEATURES - Large phone numbers database (regularly updated) - Reverse phone lookup - Company & Business identification - Caller ID - Reporting numbers - Blacklist LARGE PHONE NUMBERS DATABASE We have more than 52 000 000 phone numbers in our database. Our users are helping us by adding new phone numbers every day. We collaborate with companies to make your experience with couriers, companies, or services much smoother. REVERSE PHONE LOOKUP You can search any phone number before you call back. After you type in a number, you will find supplemental information like category, country, location, and comments from other users. There are three categories of phone numbers: spam, suspicious and trustworthy. COMPANY & BUSINESS IDENTIFICATION Number Book: Who is Calling isn't only about finding a number. An essential feature of our app is the identification of companies. You will see on your screen - service, company, and dining places. CALLER ID IDENTIFICATION Number Book: Who is Calling identifies all incoming calls. You will immediately know from which category the unknown number belongs. In some cases, you will see the company's number - for example, Uber, Bolt, Deliveroo, etc. REPORTING NUMBERS All users can add new phone numbers to our database, write comments and choose a category for all numbers. BLACKLIST Add unwanted phone numbers to your personalized blacklist. You decide which phone numbers will be automatically blocked. All mentioned features are part of premium subscription, which is mandatory for access to Who Is Calling. Auto-renewing subscription cost $1.99 monthly / $14.99 yearly - price varies by country. __________________ Privacy Policy: https://www.numbo.com/privacy-policy/ Terms of Use: https://www.numbo.com/terms-of-service/

About

PDF Reader Light & Simple

Easily read PDF files with this lightweight and fast application. It offers optimized performance for iPhones and iPads, along with bookmark management and quick navigation features. Enjoy a seamless reading experience without any advertisements.

Highlights
  • Lightweight and fast performance
  • Optimized for iPhone and iPad
  • Bookmark management
  • Fast and easy navigation
  • Ad-free experience
Features
Read full description

Read your PDF files easily with our lightweight reader ! - Optimized for both iPhones and iPad - Lightweight and super fast - Bookmark management - Fast & easy navigation - Ad free!

Screenshots

NumberBook4 screens
PDF Reader Light & Simple3 screens

Verdict

The call

The clearest difference is review sentiment: PDF Reader Light & Simple at 100% against NumberBook's 20%. PDF Reader Light & Simple also leads on in-app purchases (none vs 2). NumberBook's advantage is update cadence (every 2 months vs every 19 months) and iOS requirement (12.1 vs 15.6). On price, ads and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. NumberBook sells 2 in-app purchases, starting at $3.99 per month. PDF Reader Light & Simple asks for nothing beyond the download.

UpkeepUpdate frequency

NumberBook ships an update every 2 months, PDF Reader Light & Simple every 19 months. Both last shipped on November 3, 2026.

Scorecard5 real differences · 5 level
NumberBook versus PDF Reader Light & Simple: the parameters behind the verdict, then further details
ParameterNumberBookPDF Reader Light & Simple
PriceFreeFree
Rating2.5 (6 ratings) — better—
Positive reviews20.0% of reviews100.0% of reviews — better
Number of ratings6 — better—
Update frequencyEvery 2 months — betterEvery 19 months
AdsNoNo
In-app purchasesYesNo — better
MonetizationSubscriptionFree — better
DevicesiPhone, iPodiPhone, iPad, iPod — better
Requires iOS12.1 — better15.6
Further details — not scored
Size36 MB12 MB
Age rating4+4+
DeveloperNumbo s.r.o.Adaptive Channel

Customer experience

NumberBook

All ratings6 ratings
Positive33.3%
Neutral0.0%
Negative66.7%
Written reviews5 reviews
Positive20.0%
Neutral0.0%
Negative80.0%

PDF Reader Light & Simple

Written reviews2 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

2 purchases

NumberBook

Subscriptions2
  • Premium - one month$3.991 Month
  • Premium - one year3 Days trial$14.991 Year
None

PDF Reader Light & Simple

No in-app purchases

Questions

Is NumberBook free?
NumberBook is free to download, with in-app purchases available.
Is PDF Reader Light & Simple free?
PDF Reader Light & Simple is free to download, with no in-app purchases.
Do NumberBook or PDF Reader Light & Simple have ads?
Neither NumberBook nor PDF Reader Light & Simple shows ads.
Which is updated more often, NumberBook or PDF Reader Light & Simple?
NumberBook ships an update every 2 months, and PDF Reader Light & Simple every 19 months. Most recently, NumberBook was updated on November 3, 2026 and PDF Reader Light & Simple on November 3, 2026.

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